Improved street-pavement



UNITED STATES PATENT OFFICE.

HENRY M. sTow, 0E SAN EEANeIsco, cALIEoaNIA.

IMPROVED STREET-PAVEMENT.

Speeication forming part of Letters Patent No. 72,111, dated December 10, 1867..

To all whom 'it may concern i y Beit known that I, HENRY M. STOW, of San Francisco, in the county of San Francisco and State of California, have invented a new and useful Improvement in Street-Pave-V ments; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, forming a part of this specification.

The nature ot' my invention consists in forming a pavement of'alternate tiers ot' wedgeshaped wooden blocks and cast-iron plates, with prfliecting wedge-shaped flanges, to be driven into a foundation of sand or loose earth, as hereinafter more fully described and shown.

The drawing shows a section of my pavement lengthwise of the street, or crosswise in respect to the blocks and intermediate cast iron plates.

A A are cross-sections of the wedge-shaped wooden blocks, in the position they occupy when the pavement is completed, and A' A" are cross-sections of similar blocks not yet driven down to their places. B B B are crosssections of east-iron plates, with projecting wedge-shaped flanges b and b', and shallower flanges or ribs c e e.

The wooden blocks may be from four and a half to seven inches long, or deep-that is to say, from the square top tothe point ofthe Wedgefrom one to three inches thick, and of' any convenient width, according to the size of the lumber from which they are made. They are to be made in-wedge form by beveling one side only, as clearly shown in the drawing. 4

rIhe cast'iron plates should be from three to four inches` wide, and from one-fourth to threeeighths of an inch thick, the anges and ribs being of about the same thickness. These plates may be cast of any convenient length.A

To put down this pavement the street is first filled with a bed of sand or loose earth to the depth of the wooden blocks to be used. The cast-iron sections or plates are then to be laid down in tiers across the street, with tiers of wooden blocks between them, as shown by A in the drawings. When any desired length of pavement is thus laid, the wooden blocks are to be driven down to the position shown by A A; but before said blocks are driven the outer cast-iron plates should be so contined that the section of pavement so Alaid cannot of wooden blocks will, by the driving down of said blocks, be divided into sections, and confined in separate chambers, so that no particle oi'. sand or earth can be pressed out of its own Y chamber. Consequently said sand or earth must become greatly compressed and compacted by driving down the wedge-shaped blocks, and will form a foundation so firm that the most heavily-laden wagons, in passing over the pavement, will not in the least depress any of the blocks, or produce any unevenness in the surface ofthe pavement.

The shallower anges b on the lower side ot' the cast-iron plates are not laltogether indispensable to the'invention; but I prefer to use them. The deeper iianges b should be about halt' the depth ot' the wooden blocks. "The ribs e c o on the upper sides ot' the cast-iron plates are intended to give a foot-hold to horses and other animals traveling on the pavement. The blocks and plates should be so laid as to break joints, and the blocks may be saturated with coal or gas tar, or any oi' the liquid hydrocarbons, or with any pitchy or resinous matter `which will tend to preserve the wood from decay.

When tinl blocks are all driven down their` upper ends may be subjected to acoating of' boiling-hot coal-tar and asphaltum, or oil and asphaltum, or any other suitable pitchy substance, and then covered by a thin layer of sand.

Having thus fully described my invention, and the method ot' carrying it into effect, what I claim as new, and desire to secure by Letters Patent, is-

1. The cast-iron plates with projecting wedgeshaped anges, to be driven into the sand or earth, substantially as and for the New... Mama... ..-ma .n i..:..`..t... ...A

ill 

